package com.test01.utils;

import com.mysql.cj.protocol.Resultset;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.sql.*;
import java.util.Properties;

public class JdbcUtils {

    private static String driver = null;
    private static String url = null;
    private static String username = null;
    private static String password = null;
    static {
        try{
            InputStream inputStream = JdbcUtils.class.getClassLoader().getResourceAsStream("db.properties");
            Properties properties = new Properties();
            properties.load(inputStream);

            driver = properties.getProperty("driver");
            url = properties.getProperty("url");
            username = properties.getProperty("username");
            password = properties.getProperty("password");

            //1.驱动只用加载一次
            Class.forName(driver);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //获取连接
    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(url, username, password);
    }

    //释放连接
    public static void releaseConnection(Connection connection, Statement statement, ResultSet resultset){
        if (resultset!=null){
            try {
                resultset.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (statement!=null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection!=null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }



    }
}
